Sounds good!
I'd say a daylight reduction under the sills would help a treat...yes yes you need some mounts!...lol...I'm on the chase again!
There will be another MK1 with some chassis tweeks keeping you company next year too...

Get the engine apart Sam...do a basic compression test first & check the cam timing via lift @ tdc...oh and the ignition / fueling on some rollers to get a current power output would help.